Tiller, bow and trigger mechanism for a crossbow, and a crossbow

ABSTRACT

The invention relates to a tiller for a crossbow which has a cocking lever in the form of an upper arm ( 1 ) and a lower arm ( 2 ) pivotally connected with each other about an axis (X) in the front part of the tiller, whereas in the rear part of the tiller said upper arm ( 1 ) is connected with the upper end of a butt ( 5 ), and said lower arm ( 2 ) is connected with the lower end of the butt ( 5 ) in the folded state of the tiller by means of a snap fastener ( 6 ). Said tiller for a crossbow can be assembled with any appropriate bows and trigger mechanisms, but preferably it is used with a novel bow for a crossbow which is also disclosed.

BACKGROUND OF THE INVENTION

The invention relates to a tiller and bow for a crossbow, and to acrossbow containing at least one of the aforementioned parts.

Crossbows having a bow (or prod) equipped with pulleys for a bowstringmounted on a tiller provided with a butt, trigger mechanism and aimingdevice, cocked by means of various cocking mechanisms, have been knownfor long time.

EP 0 132 017 B1 discloses a crossbow having a tiller which carries aprod and a bowstring arrestor, and having a release mechanism. Said prodis mounted for reciprocal movement relative to the tiller to facilitatecocking the bow. The crossbow is cocked with the use of a cockingmechanism comprising a crank lever which has one of its ends pivotallymounted to the stock by means of a stock pin and has its opposite endpivotally connected between the ends of a connecting lever by means of acrank pin. The “slider” of the cocking mechanism comprises a draw blockto which one end of the connecting lever is mounted by means of a blockpin. The connecting lever extends beyond the pivotal connection at thecrank pin to provide a grip portion by which the cocking mechanism canbe operated. To cock the bow the grip portion of the connecting lever ismanipulated so that it is pushed away from the stock to pivot about theblock pin. This action causes the draw block to slide along a forendtube towards an adjacent shoulder of the stock, whereby the grip and thebowstring are moved rearwardly together, as a unit. The crossbow stockis provided with a bowstring arrestor and release mechanism whichautomatically arrests the bowstring when it enters the mechanism. Inthis known cocking mechanism the crank lever is relatively short whichlimits possible maximum launch force.

EP 0 223 797 B1 discloses a crossbow equipped with an integrated drawingdevice which is supposed to facilitate fast cocking of the bowstring andplacing said mechanism in a position where it does not hinder handlingthe crossbow and shooting. In this known solution the drawing deviceconsists of two elements, a pusher and a draw lever rotatably mounted ina support of the crossbow to pivot about a horizontal axis transverse tothe longitudinal axis of said support. Said axis is situated in thefront part of a metal insert between a bow and a bowstring. In its lowerpart the draw lever is provided with a longitudinally extending recessinto which the pusher of lesser thickness engages and is hinged at apoint of rotation at a certain distance from said axis. The recess is sodimensioned that it can completely receive the pusher in the insertedposition of the drawing device, except for its free end. This free endexhibits an indentation which in the drawing operation can engage acomplementary or positively formed projection of trigger slide. With amovement of draw lever from the rest position toward the back end of thecrossbow trigger slide is pressed back until it engages a holder of thetrigger device. To be able to guarantee a flawless functioning, thedistance of said axis from the point of rotation must be a little morethan half the draw travel of the trigger slide or of the bowstring. Tobe able to house the drawing device inconspicuously and withouthindering the shooting operation after the drawing operation, the metalinsert and the adjacent front part of the support are provided withcorresponding longitudinal groove sections which are so dimensioned thatthe drawing device when folded back into the extended (rest) position,together with the pusher in the recess of the draw lever, is completelyreceived by the support. To avoid an automatic release of the drawingdevice from the rest position the draw lever is locked in the support bya latch provided on the front end of support, which engages in a notchon the front end of the draw lever. To eliminate any movement of theprojectile guide in relation to the aiming device in this known crossbowextremely precise dimensional tolerances must be strictly observedduring its manufacturing, which significantly increases productioncosts. Due to the structure of the cocking system the drawing force ofthis known crossbow is relatively small.

To the best knowledge of the applicant, there is no relevant prior artas far as the inventive bow and trigger mechanism are concerned.

SUMMARY OF THE INVENTION

The object of this invention is to provide modular parts of a crossbowwhich when combined with each other or when combined with suitableelements of various known crossbows, will overcome the aforementionedproblems.

One aspect of the invention provides a tiller for a crossbow having acocking lever in the form of an upper arm and a lower arm, said armsbeing pivotally connected with each other about an axis in the frontpart of the tiller, whereas in the rear part of the tiller said upperarm is connected with the upper end of a butt, and said lower arm isconnected with the lower end of the butt in the folded state of thetiller by means of a snap fastener.

Another aspect of the invention provides a bow for a crossbow withpulleys for a bowstring, said bow having two limbs, the first limbhaving on its respective ends a front pulley and a back pulley, and asecond limb having on its respective ends a front pulley and a backpulley, said limbs being pivotally connected by means of bolts with acentral cross-bar carrying a pre-cocking mechanism to which a bowstringis fastened, wherein the first end of the bowstring is fastened to thepre-cocking mechanism on its side facing the second limb, from where thebowstring runs to the front pulley of the first limb and then, along thediagonal of the bow, to the back pulley of the second limb, and then tothe back pulley of the first limb from where it runs, along the diagonalof the bow, to the front pulley of the second limb and then to the placeat which its second end is fastened, said place being situated on thepre-cocking mechanism on its side facing the first limb.

In a preferred embodiment said bow limbs are provided at their both endswith recesses in which the pulleys are fixed and through which thebowstring runs.

Preferably the recesses are triangular with vertices directed towardsthe middle of the limbs.

In a preferred embodiment of the bow of the invention the pre-cockingmechanism is positioned centrally between the limbs, and has a body witha longitudinal slotted guide for a draw pin, said guide passing throughsaid body in the direction of the limbs, and the ends of the bowstringare fastened on the sides of the body to the ends of the draw pin fromwhere the bowstring runs to the front pulleys of the limbs, through anotch on the top of the body adjacent to a threaded hole for a drawscrew connected with the draw pin.

Preferably the slotted guide and the threaded hole for the draw screware situated diagonally in relation to the longitudinal axis of thebody.

Another aspect of the invention provides a crossbow having a cockingmechanism and a bow with pulleys for a bowstring, said bow being mountedon a tiller including a projectile guide and provided with an aimingmechanism and a trigger mechanism, characterized by having the abovedefined tiller of the invention as its tiller and the above defined bowof the invention as its bow.

It is to be understood that the crossbow of the invention can beassembled by combining any suitable conventional bow and any suitableconventional trigger mechanism with the tiller of the invention; or bycombining any suitable conventional tiller and any suitable conventionaltrigger mechanism with the bow of the invention; or by combining anysuitable conventional trigger mechanism with the tiller of the inventionand the bow of the invention.

In preferred embodiments of the invention the crossbow of the inventionhaving the bow of the invention has preferred features defined above inrelation to said bow.

Preferred trigger mechanism for the crossbow of invention has a casecontaining a nut in the form of a cylinder with a cut-out for thebowstring and an indentation located oppositely to said cut-out andaccommodating a first ball from a set of at least two locking ballspositioned one on the top of the other in the case, wherein the nut isconnected with an stopper which abuts a spring-loaded retainer for saidstopper, and the set of locking balls includes a working ball which onits one side is co-axially adjacent to a pusher connected with atrigger, and on its opposite side is adjacent to a working element of acounterrecoil mechanism, said working element being loaded with a recoilspring.

Preferably the trigger mechanism has the working element in the form ofa ball.

Such a trigger mechanism is sturdy but simultaneously it has a highsensitivity, and thus requires a minimal force to release the bowstringfor shooting a projectile. It provides also a high safety, as thetrigger mechanism is easily protected against self-release by blockingthe working element (ball) of a counterrecoil mechanism.

The crossbow of the invention can be used for any purpose, as a huntingcrossbow, for sports competitions, to put animals to sleep, as a weaponetc. It can be adapted for any projectiles, e.g. arrows, bolts, harpoonsand narcotising projectiles.

The tiller of the invention provides a cocking mechanism in thescissors-like form which allows to cock the crossbow by applying aminimal force to the end of the lower arm of the cocking lever.

Due to the modular construction of the bow it can be readily mounted onor removed from the tiller, which enables fast assembling anddismantling of the crossbow. This makes it very convenient for handlingand transporting. Furthermore the structure of the bow results in thesubstantial reduction of the kick effect and diminishes the impact ofinertial force on the person shooting the crossbow.

Furthermore the bow of the invention has a distinct advantage in that itcan be up to 50% narrower than various conventional bows, and yet itstill ensures exceptionally good cocking parameters. The structure ofthe bow, and in particular its pivotal connection about the bolts,provides for considerable reduction of friction between the bowstringand the projectile guide when the bowstring is drawn.

The structure of the modular parts of the crossbow, i.e. of the tillerand the bow, makes it possible to assembly a compact crossbow of a smallwidth, easy to cock with a minimal effort, yet providing a large drawforce. The crossbow is fast-firing and allows for dischargingprojectiles with a high initial velocity.

BRIEF DESCRIPTION OF THE DRAWINGS

Additional objects and advantages of the invention will become apparentto those skilled in the art upon reference to the detailed descriptionof the invention in connection with the accompanying drawing wherein:

FIG. 1 is a top view of a crossbow of the invention having a tiller andbow of the invention.

FIG. 2 is a side view of a crossbow of the invention having a tiller andbow of the invention.

FIG. 3 is a side view of a disassembled tiller of the invention providedwith a trigger portion and aiming device.

FIG. 4 is a side view of a crossbow of the invention with its tilleropen and ready for drawing a bowstring.

FIG. 5 is a perspective view of a bow of the invention.

FIG. 6 is a top view of a bow of the invention in its uncocked state.

FIG. 7 is a top view of a bow of the invention in its cocked state.

FIG. 8 is a top view with a part section of a pre-cocking mechanism in abow with a non-drawn bowstring.

FIG. 9 is a side view of the pre-cocking mechanism of FIG. 8.

FIG. 10 is a top view with a part section of a pre-cocking mechanism ina bow with a drawn bowstring.

FIG. 11 is a side view of the pre-cocking mechanism of FIG. 10.

FIG. 12 is a schematic view of a preferred trigger mechanism to be usedin the crossbow of the invention at its blocked position.

FIG. 13 is a schematic view of a trigger mechanism of FIG. 12 after thebowstring has been released.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a crossbow of the invention in its uncocked state with itstiller folded and snapped, as described below.

FIGS. 2, 3 and 4 show the crossbow of FIG. 1, folded, disassembled (onlythe tiller, aiming device and trigger portion are shown) and unfoldedrespectively.

The tiller on which the bow (12) is mounted has a cocking lever in theform of two arms, an upper arm 1 and a lower arm 2, which are pivotablyconnected about an axis X in the front part of the tiller.

The upper arm 1 has a projectile guide 3 which abuts a butt bracket 4through which the upper arm 1 is connected with the butt 5 in the rearpart of the tiller.

The upper arm 1 is connected with the upper end of a butt 5, and saidlower arm 2 is connected in the folded state of the tiller with thelower end of the butt 5 by means of a rear snap fastener 6. The rearsnap fastener 6 is formed by a finger 7 a on the butt 5 and a hook 7 bat the end of the lower arm 2.

A trigger mechanism 8, described with details further below, is situatedbetween the arms 1 and 2. In the folded state of a tiller the triggermechanism 8 is connected with the lower arm 2 by means of a front snapfastener 9. The front snap fastener 9 consists of a finger 10 a situatedon the trigger mechanism 8, in its bottom part, and a hook 10 b locatedon the lower arm 2 of the cocking lever.

In the region of the projectile guide 3 a conventional aiming mechanism11 is mounted.

FIGS. 5, 6 and 7 show the bow 12 of the invention which can be mountedon a conventional tiller or on the tiller of the invention. The bow 12is pivotably connected about an axis X1 with the lower arm 2 of thecocking lever, said axis X1 being positioned at a certain distance fromthe axis X. The bow 12 has two limbs 13, 14, both provided on theirrespective ends with front pulleys 15 a, 15 b and back pulleys 16 a, 16b. The limbs 13, 14 are pivotally connected by means of bolts 17 a, 17 bwith a central cross-bar 18 which carries a pre-cocking mechanism 19 towhich a bowstring 20 is fastened. The limbs 13, 14 can be positionedparallel to the shot axis, but their rotatable attachment to the centralcross-bar 18 allows to deflect them in relation to the plane of shotdetermined by the tiller and the central cross-bar 18, at a small angleto the shot axis. Such a deflection is advantageous since it reducesfriction of the bowstring 20 against the projectile guide 3. The bow 12can be fixed to the tiller with the use of any suitable locking means,e.g. a bayonet lock (not shown).

The bowstring 20 is fastened to a pre-cocking mechanism 19 and guided bythe pulleys 15 a, 15 b, 16 a, 16 b. The first end of the bowstring 20 isfastened to the pre-cocking mechanism 19 on its side facing the secondlimb 14. From this point of fixation the bowstring 20 runs to the frontpulley 15 a of the first limb 13 and then, along the diagonal of the bow12 to the back pulley 16 b of the second limb 14, and then to the backpulley 16 a of the first limb 13 from where it runs, along the diagonalof the bow 12, to the front pulley 15 b of the second limb 14 and thento the place at which its second end is fastened, said place beingsituated on the pre-cocking mechanism 19 on its side facing the firstlimb 13.

In a preferred embodiment the limbs 13, 14 of the bow 12 are providedwith recesses 21, advantageously of substantially triangular shape withvertices directed to the middle of the limbs. The pulleys 15 a, 15 b, 16a, 16 b are mounted on their axles in the recesses 21 and the bowstring20 passes through said recesses.

The bow 12 is provided with a pre-cocking mechanism, in a preferredembodiment designed as shown in FIG. 8–11.

The pre-cocking mechanism 19 is positioned centrally between the limbs13, 14. It has a body 22 with a longitudinal slotted guide 23 for a drawpin 24. The guide 23 passes through said body 22 and has its respectiveoutlets facing the limbs 13, 14. The ends of the bowstring 20 arefastened on the sides of the body 22 to the ends of the draw pin 24.From these fixation sites the bowstring 20 runs to the front pulleys 15a, 16 a of the limbs 13, 14 through a notch 25 on the top of the body 22adjacent to a threaded hole for a draw screw 26 connected with the drawpin 24. In a preferred embodiment the slotted guide 23 and the threadedhole for the draw screw 26 are situated diagonally in relation to thelongitudinal axis of the body 22.

FIGS. 12 and 13 show a preferred trigger mechanism for the crossbow ofthe invention with the bowstring 20 arrested and released respectively.

The trigger mechanism 8 has a case 27 containing a nut 28 in the form ofa cylinder with a cut-out 29 for the bowstring 20, and an indentation 30located oppositely to said cut-out 29 and accommodating a first ball 31from a set of at least two locking balls 31 positioned one on the top ofthe other in the case 27. The indentation 30 is shown as spherical, yetit can have a form of any cut-out able to accommodate the first ball 31.The nut 28 is connected with an stopper 32 which forces the return ofthe nut 28 to its pre-shot position in which the bowstring 20 can beintroduced into the nut 28 through the slot 39 in the case 27 of thetrigger mechanism. The stopper 32 abuts a spring-loaded retainer 33 ofthe stopper 32.

The set of locking balls 31 includes a working ball 34 which on its oneside is co-axially adjacent to a pusher 35 connected with a trigger 36,and on its opposite side is adjacent to a working element 37 of acounterrecoil mechanism, said working element 37 being loaded with arecoil spring 38. In the shown embodiment the working element 37 is aball.

The mode of operation of the above-described crossbow is as follows.

The bow 12 with the bowstring 20 pre-drawn by means of the pre-cockingmechanism 19 is mounted on the tiller. To shot the crossbow thebowstring 20 must be fully drawn. For this purpose the rear snapfastener 6 and the front snap fastener 9 are opened and the lower arm 2is turned in relation to the upper arm 1 about the axis X, whichsimultaneously causes certain pivotal movement about the axis X1 andshifts the bow 12 towards the trigger mechanism 8. This combineddisplacement of the bow 12 shifts the bowstring 20 along the projectileguide 3 towards the trigger mechanism 8 and introduces the bowstring 20through the slot 39 in the case 27 into the cut-out 29 in the nut 28.The action of the bowstring 20 on the surface of the cut-out 29 turnsthe nut 28 to the right, and the verge of the indentation 30 movestowards the top of the nearest locking ball 31 in the set of lockingballs. As soon as said verge passed the top of said nearest locking ball31, the ball slips into said indentation under the pressure of theelement 37 loaded with the spring 38, and this action causes furtherrotation of the nut 28 which arrests the bowstring 20 within the cut-out29. As shown in FIG. 12, at this moment the bowstring 20 is accommodatedin the cut-out 29 which is positioned at the top of the nut 28 and thestopper 32 on the nut 28 is deflected at the angle of about 60° from thevertical axis of the case 27.

A final draw to the bowstring 20 is applied by folding the tiller, i.e.by turning the lower arm 2 of the cocking lever back till the front snapfastener 9 and the rear snap fastener 6 are both snapped. When aprojectile is placed in the projectile guide 3, the crossbow is ready tobe shot.

When the trigger 36 is pulled, the set of locking balls 31 becomesdestabilized since the pusher 35 pushes out one of the balls 31 whichacts as a working ball 34. The working ball 34 pushes the workingelement 37 of a counterrecoil mechanism which is loaded with the recoilspring 38. The draw force of the bowstring 20 turns the nut 28 by about60° to the left till its rotation is stopped by the stopper 32. At thismoment the cut-out 29 is aligned with the slot 39 in the case 27 of thetrigger mechanism 8, the bowstring 20 is released and the crossbowdischarges the projectile. The stopper 32 is retained in its topmostposition by the retainer 32 which is loaded with a spring. Thisretaining system is shown as placed partially outside the case 27 but ofcourse it is possible to have it fully integrated within the triggermechanism in its case 27.

To shot the crossbow again, this simple cocking procedure is repeated.

1. A tiller for a crossbow (12) characterized in that it has a cockinglever in the form of an upper arm (1) and a lower arm (2) pivotallyconnected with each other about a first axis (X) in the front part ofthe tiller, said first axis (X) is positioned at a certain distance froma second axis (X1) situated at an end of the lower arm (2) for mountingthe crossbow bow (12), whereas in the rear part of the tiller said upperarm (1) is connected with the upper end of a butt (5), and said lowerarm (2) is connected with the lower end of the butt (5) in the foldedstate of the tiller by means of a snap fastener (6).
 2. The tiller ofclaim 1 wherein said crossbow (12) pivotably connects with the lower arm(2) about said second axis (X1).
 3. A bow for a crossbow with pulleysfor a bowstring, characterized in that it has two limbs (13, 14), thefirst limb (13) having on its respective ends a front pulley (15 a) anda back pulley (16 a), and a second limb (14) having on its respectiveends a front pulley (15 b) and a back pulley (16 b), said limbs (13, 14)being pivotally connected by means of bolts (17 a, 17 b) with a centralcross-bar (18) carrying a pre-cocking mechanism (19) to which abowstring (20) is fastened, wherein the first end of the bowstring (20)is fastened to the pre-cocking mechanism (19) on its side facing thesecond limb (14), from where the bowstring (20) runs to the front pulley(15 a) of the first limb (13) and then, along the diagonal of the bow(12), to the back pulley (16 b) of the second limb (14), and then to theback pulley (16 a) of the first limb (13) from where it runs, along thediagonal of the bow (12), to the front pulley (15 b) of the second limb(14) and then to the place at which its second end is fastened, saidplace being situated on the pre-cocking mechanism (19) on its sidefacing the first limb (13).
 4. A bow for a crossbow according to claim3, characterized in that said limbs (13, 14) are provided at their bothends with recesses (21) in which the pulleys (15 a, 15 b, 16 a, 16 b)are fixed and through which the bowstring (20) runs.
 5. A bow for acrossbow according to claim 4, characterized in that the recesses (32)are triangular with vertices directed towards the middle of the limbs(13, 14).
 6. A bow for a crossbow according to claim 4, characterized inthat the slotted guide (23) and the threaded hole for the draw screw(26) are situated diagonally in relation to the longitudinal axis of thebody (22).
 7. A bow for a crossbow according to claim 3, characterizedin that the pre-cocking mechanism (19) is positioned centrally betweenthe limbs (13, 14) and has a body (22) with a longitudinal slotted guide(23) for a draw pin (24), said guide (23) passing through said body (22)in the direction of the limbs (13, 14), and the ends of the bowstring(20) are fastened on the sides of the body (22) to the ends of the drawpin (24) from where the bowstring (20) runs to the front pulleys (15 a,16 a) of the limbs (13, 14) through a notch (25) on the top of the body(22) adjacent to a threaded hole for a draw screw (26) connected withthe draw pin (24).
 8. A crossbow having a cocking mechanism and a bowwith pulleys for a bowstring, said bow being mounted on a tillerincluding a projectile guide and provided with an aiming mechanism and atrigger mechanism, characterized in that the tiller of said crossbow hasa cocking lever in the form of an upper arm (1) and a lower arm (2)pivotally connected with each other about an axis (X) in the front partof the tiller, whereas in the rear part of the tiller said upper arm (1)is connected with the upper end of a butt (5), and said lower arm (2) isconnected with the lower end of the butt (5) in the folded state of thetiller by means of a snap fastener (6); the bow of said crossbow has twolimbs (13, 14), the first limb (13) having on its respective ends afront pulley (15 a) and a back pulley (16 a), and a second limb (14)having on its respective ends a front pulley (15 b) and a back pulley(16 b), said limbs (13, 14) being pivotally connected by means of bolts(17 a, 17 b) with a central cross-bar (18) carrying a pre-cockingmechanism (19) to which a bowstring (20) is fastened, wherein the firstend of the bowstring (20) is fastened to the pre-cocking mechanism (19)on its side facing the second limb (14), from where the bowstring (20)runs to the front pulley (15 a) of the first limb (13) and then, alongthe diagonal of the bow (12), to the back pulley (16 b) of the secondlimb (14), and then to the back pulley (16 a) of the first limb (13)from where it runs, along the diagonal of the bow (12), to the frontpulley (15 b) of the second limb (14) and then to the place at which itssecond end is fastened, said place being situated on the pre-cockingmechanism (19) on its side facing the first limb (13).
 9. A crossbowaccording to claim 8, characterized in that said limbs (13, 14) of thebow (12) are provided at their both ends with recesses (21) in which thepulleys (15 a, 15 b, 16 a, 16 b) are fixed and through which thebowstring (20) runs.
 10. A crossbow according to claim 9, characterizedin that the recesses (32) are triangular with vertices directed towardsthe middle of the limbs (13, 14).
 11. A crossbow according to claim 8,characterized in that in the bow (12) the pre-cocking mechanism (19) ispositioned centrally between the limbs (13, 14) and has a body (22) witha longitudinal slotted guide (23) for a draw pin (24), said guide (23)passing through said body (22) in the direction of the limbs (13, 14),and the ends of the bowstring (20) are fastened on the sides of the body(22) to the ends of the draw pin (24) from where the bowstring (20) runsto the front pulleys (15 a, 16 a) of the limbs (13, 14) through a notch(25) on the top of the body (22) adjacent to a threaded hole for a drawscrew (26) connected with the draw pin (24).